The present invention relates to a damper having a simple configuration and a compact size.
A damper is used for, for example, a glove box, etc. provided inside a vehicle. When a lid of the glove box is opened, the damper controls the lid to rotate at an appropriate speed.
For example, in Japanese Patent Publication (Tokkai) No. 2002-5213, a damper 200 shown in FIG. 11 includes a cylinder 202 with an open end. A cover member 206 having a through-hole 204 at the center thereof is fitted in the open end.
A piston rod 212 formed of a piston 208 and a shaft 210 is placed in the cylinder 202, and is able to move along an axis direction of the cylinder 202. The piston rod 212 is disposed on an axis same as that of the cylinder 202, and has a length so that an end part of the shaft 210 is exposed from the cylinder 202 through the through-hole 204 when the piston 208 is situated at a bottom of the cylinder 202. The end part of the shaft 210 is attached to the lid of the glove box (not shown), and the piston rod 212 moves inside the cylinder 202 when the lid opens and closes.
A depressed part 214 is formed on an outer circumferential face of the piston 208 along a periphery of the piston 208. A seal ring 216 is fitted in the depressed part 214. The seal ring 216 contacts an inner circumferential face of the cylinder 202 to produce frictional resistance between the inner circumferential face of the cylinder 202 and the seal ring 216 when the piston rod 212 moves, hereby obtaining a damper effect.
A coil spring 218 is disposed around the outer circumferential face of the shaft 210. One end part of the coil spring abuts against the cover member 206, and the other end part thereof abuts against a top face of the piston 208. When the piston 208 is moved toward the cover member 206, the coil spring 218 is compressed in the direction against the urging force thereof and assists the damper effect.
A pair of vibration prevention rockers 220, 222 is projected on the outer circumferential face of the shaft 210 along the axial direction of the shaft 210 to prevent the coil spring 218 from vibrating when the coil spring 218 is compressed.
The coil spring 218 is provided between the piston 208 and the covering member 206. Accordingly, it is necessary to provide a space for the coil spring 218 in a state where the piston 208 is located in a position closest to the covering member 206, thereby making it difficult to reduce a size of the cylinder 202. Further, the covering member 206 for holding the coil spring 218 is necessary, thus it is difficult to reduce the number of the parts.
The present invention has been made in view of the problems described above, and an object of the present invention is to provide a damper having a compact size with a simple configuration.
Further objects and advantages of the invention will be apparent from the following description of the invention.